"After age 30, most men begin to experience a gradual decline in testosterone," says David Samadi, MD, chairman of the urology department at Lenox Hill Hospital in nyc.

Though testosterone levels never reach zero (as estrogen levels do in women during menopause), low testosterone levels men to experience symptoms such as fatigue, low sex drive, and loss of muscle mass.

While reduced testosterone is more prevalent in older men, it may occur in younger men also. Fortunately, all of the causes of low testosterone in young guys are curable, so if you encounter these symptoms at any given age, there's no reason to ignore it.

Causes of Low Testosterone in Younger Men

For younger men, a drop in testosterone levels can be caused by some illnesses, including type 2 diabetes, diabetes, chronic liver or kidney disease, COPD or other lung disease, or adrenal gland problems, according to Dr. Samadi.

Genetic causes of low testosterone in men include the ailments Klinefelter syndrome, Kallmann syndrome, Prader-Willi syndrome, and Myotonic dystrophy. Another disorder which could cause low testosterone is hemochromatosis, making the body shop too much iron.

"Low testosterone can also result when something happens, like trauma or steroid use, that prevents the testes from making the hormone," says Bruce Gilbert, MD, PhD, an adjunct clinical professor of urology and reproductive medicine at Weill Cornell Medical College and director of reproductive and reproductive medicine at the Smith Institute for Urology of the North Shore-LIJ Health System.

Additional causes of low testosterone in men younger than 50 contain adrenal gland tumors, HIV disease, and radiation treatment or chemotherapy for cancer.

Doctors categorize causes of low testosterone as primary or secondary.

"Primary hypogonadism stems from a problem in the testicles," Samadi states. "This could be from a developmental issue, injury to the testicles, or radiation or chemotherapy treatment. In secondary hypogonadism, the testicles are normal but function improperly because of a problem with the hypothalamus or pituitary gland."

"Younger men with low testosterone usually come to me and say, 'I can't work out like I used to, and I've lost interest in sex.’ ”

If you suspect low testosterone, the first step is to see your primary care physician.

Treatments for Low Testosterone in Younger Men

Not everyone with low testosterone needs treatment. "When it comes to treating low testosterone in older guys, we usually reserve treatment for people who have symptoms, such as fatigue and reduced libido," Gilbert says.

Such testosterone supplements come in the form of gel, injections, patches, long-acting pellets, or oral inserts.

In these circumstances,"treatments are often used only in the brief term, and when a doctor has close monitoring and understanding of the individual," Gilbert says.

An important consideration for younger men before getting treatment is fertility. "You don't wish to offer supplemental testosterone to guys who are interested in being fertile since it can turn off sperm production," Gilbert says.

Once a young man goes off testosterone supplementation, there's a chance his sperm count will never return to what it was before he started. "Hence, men of reproductive age should think about alternatives which may improve their testosterone in addition to preserve their sperm production," he says. One such alternative is a category of drugs known as selective estrogen receptor modulators (SERMs).

Other remedies for low testosterone include weight loss and other lifestyle modifications, like eating healthier and increasing exercise.

The bottom line, though, is that in the event that you've got low testosterone symptoms, then it is important to see your doctor. Then, your doctor can rule out potentially more serious causes of your symptoms, including hypertension or a thyroid problem, and give treatment that could enhance your energy and quality of life.